Spriter is a great tool to make animated sprites in a “modular way”, which means that, we don’t have to use a complete image every single frame, instead we can animate only the necessary parts of the sprite, and play that animation. Somehow similar to a 3D animation, but in 2D.
But, Spriter use it own format (.scml) that need to be supported by the game engine. The developer of Spriter and the community is try to support some popular engines by making plugins, but GD is not one of them and those plugins are not really great. I think it could benefit GD if Spriter own animation format would be officially supported in GD because in my opinion Spriter is a great idea, would be a great feature of GD, I think if you officially support Spriter, you could also change banner with the developer of Spriter too, this way you could advertise Spriter here as a great tool and cool feature of GD, and he would advertise GD there (maybe).
But would be a great feature to support Spriter anyway. In Spriter we can keep separate and name every animations like, walk, jump…etc. If we could import Spriter animation in to GD, we could have some Spriter specific actions and conditions to play and stop animations of spriter objects.
if w is pressed : play spriter animation "jump" of object
Of course, Spriter can export animations in to .png images, but that means hundreds of frames, would be a lot more convenient if GD could import and use Spriter own (.scml) format out of the box.